E5CNH E5AN-H E5EN-H Digital Controllers User's Manual - OMRON

Position-proportional Control Section 4-24
4-24 Position-proportional Control
Closed Control
Floating Control
The control method used to adjust the opening and closing of a valve with a
control motor is called "position-proportional control" or "ON/OFF servo control."
Either closed control or floating control can be selected for position-proportional
control. Only models that support position-proportional control
(E5AN/EN-HPRR@) can be used for position-proportional control. In addition,
the following functions are disabled when using position-proportional control.
ST
LBA
Heater burnout, heater short, and heater overcurrent alarms
ON/OFF control
P and PD control (for floating control only)
40% AT (for floating control only)
Closed control provides control using feedback on the valve opening by connecting
a potentiometer.
Floating control provides control without using feedback on the valve opening,
so control is still possible even if a potentiometer is not connected. With floating
control, the expected valve opening is calculated from the travel time, and
that value is treated as the valve opening for executing control outputs.
If there is no FB input, then even if the Closed/Floating parameter is set to
Closed the parameter will be disabled and floating control will be executed.
Parameter Setting range Unit Default
Travel Time 1 to 999 s 30
Motor Calibration and Travel Time
Calibrate the motor when a potentiometer is connected, such as in closed
control or in floating control for monitoring valve opening. The fully closed and
fully open valve positions will be calibrated and the travel time, i.e., the time
from the fully open to the fully closed position, will be automatically measured
and set. Set the Motor Calibration parameter to ON to execute the motor calibration.
The setting will be automatically changed OFF when the calibration
has been completed.
For floating control (i.e., without a potentiometer connection), it is necessary
to manually set the travel time. Set the Travel Time parameter to the time from
the fully open to the fully closed valve position.
Parameter Setting range Unit Default
Motor Calibration OFF, ON --- OFF
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